Gripping devices and methods thereof

ABSTRACT

A device for gripping a cylindrical object comprises two gripping springs and an actuator, wherein: each gripping spring comprises a first end, a second end opposite the first end, and an arcuate section disposed therebetween; the gripping springs are disposed on the device such that the first ends are pivotally coupled to the device, and the arcuate sections oppose each other so as to define an opening through which the cylindrical object is inserted; and the actuator is mechanically coupled to at least one of the second ends of the gripping springs such that movement of the actuator causes the arcuate sections of the gripping springs to grip the cylindrical object when inserted into the opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. patent application Ser. No.12/622,033 filed Nov. 19, 2009 which claims priority to U.S. ProvisionalPatent Application Ser. No. 61/116,128, filed Nov. 19, 2008.

TECHNICAL FIELD

Embodiments disclosed herein relate generally to gripping devices andrelated methods, and, more particularly, to devices, systems and methodsfor removing a cap from a cylindrical object.

BACKGROUND

Presently there is a need to quickly and efficiently remove caps orstops from cylindrical (e.g., round or elliptical) objects such as testtubes. Manual removal of caps is both painful and labor intensive, andalso yields poor results. Current automatic cap removal methods areexpensive because they rely on complex machinery that requires largeactuating forces with respect to gripping force. Further, currentremoval methods do not provide for self-centering of the test tube,making cap removal automation a difficult endeavor.

SUMMARY

In one embodiment, a device for gripping a cylindrical object comprisestwo gripping springs and an actuator, wherein: each gripping springcomprises a first end, a second end opposite the first end, and anarcuate section disposed therebetween; the gripping springs are disposedon the device such that the first ends are pivotally coupled to thedevice, and the arcuate sections oppose each other so as to define anopening through which the cylindrical object is inserted; and theactuator is mechanically coupled to at least one of the second ends ofthe gripping springs such that movement of the actuator causes thearcuate sections of the gripping springs to grip the cylindrical objectwhen inserted into the opening.

In another embodiment, a system for removing a cap from a cylindricalcontainer comprises a plurality of gripping devices, an indexing table,and a decapping assembly, wherein: each of the gripping devicescomprises two gripping springs and an actuator, wherein: each grippingspring comprises a first end, a second end opposite the first end, andan arcuate section disposed therebetween; the gripping springs aredisposed on the system such that the first ends are pivotally coupled tothe system, and the arcuate sections oppose each other so as to definean opening through which the cylindrical container is inserted; and theactuator is mechanically coupled to at least one of the second ends ofthe gripping springs such that movement of the actuator causes thearcuate sections of the gripping springs to grip the cylindricalcontainer when inserted into the opening; the plurality of grippingdevices are disposed on the indexing table, such that the indexing tableis configured to mechanically couple the decapping assembly to one ofthe plurality of gripping devices; and the decapping assembly isconfigured to remove the cap from the cylindrical container.

In yet another embodiment, a method for gripping a cylindrical objectwith two gripping springs comprises: providing the two gripping springs,each comprising an arcuate section disposed to oppose each other so asto define an opening through which the cylindrical object is inserted;inserting the cylindrical object into the opening defined by the twoarcuate sections of the two gripping springs; and actuating the twogripping springs such that the arcuate sections engage the cylindricalobject so as to grip the cylindrical object and prevent its rotation.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description will be more fully understood in viewof the drawings in which:

FIG. 1 is a perspective view of a gripping device gripping a cylindricalobject according to one embodiment;

FIGS. 2A and 2B is a perspective view of gripping springs according toone embodiment;

FIGS. 3A and 3B depict the ratio between the gripper torque and theactuator torque according to one embodiment;

FIG. 4 is a side elevational view of a cap removal system according toone embodiment;

FIG. 5 is a top planar view of a cap removal system according to oneembodiment;

FIG. 6 is a top planar view of a plurality gripping devices secured toan index table according to one embodiment;

FIG. 7 is a perspective view of the plurality of gripping devicessecured to an index table illustrated in FIG. 6;

FIG. 8 is a partial exploded view of a plurality of gripping devicessecured to an index table according to one embodiment; and

FIG. 9 illustrates an exploded view of a cap gripping assembly accordingto one embodiment.

The embodiments set forth in the drawings are illustrative in nature andare not intended to be limiting of the invention defined by the claims.Moreover, individual features of the drawings and the invention will bemore fully apparent and understood in view of the detailed description.

DETAILED DESCRIPTION

Embodiments described herein relate generally to gripping devices, and,more particularly, to devices, systems and methods for grippingcylindrical objects and/or removing a cap from a cylindrical object. Thecylindrical object may assume a number of different geometric shapes,sizes, and/or cross sections such as, for example, round or ellipticalshapes. The cylindrical object may have a symmetric cross section (e.g.,a round tube, oval tube, hexagonal, etc. or may have an asymmetric crosssection. Furthermore, the edge of the cylindrical objects may havecurvilinear sections, linear sections, and combinations thereof (e.g., a“D”-shaped cross section). As an example, the cylindrical object mayhave a hexagonal cross section, such that its edge has six linearsections. In some embodiments, the cylindrical object may be acylindrical container such as, for example, a test tube. In otherembodiments, the cylindrical object may be a substantially cylindricalplug or cap for plugging or capping a cylindrical container such as atest tube.

As set forth above and for illustration purposes only, the cylindricalobject may be a test tube. Many test tubes are fragile and require carein removing a cap or plug therefrom. By the use of gripping springs andother elements, such as driving and actuating links, embodimentsdescribed herein are capable of generating effective gripping forceswith minimal actuating forces. The gripping springs may be configured towrap around and firmly secure the cylindrical object. Further,embodiments comprise compliant gripping springs that provide for selflocking and self-centering of the cylindrical object within one or moreof the gripping devices set forth herein. The linkages may be rotated sothat the gripping springs grip the cylindrical object by any number ofrotational methods, such as manual rotation, servo motor, rotarysolenoid, rotary pneumatic motor, cam plate and many others. Thegripping devices described herein are capable of gripping cylindricalobjects of many different diameters and/or sizes.

Reference will now be made in detail to various embodiments which areillustrated in the accompanying drawings, wherein like numerals indicatesimilar elements throughout the views. The embodiments depicted in thedrawings are intended to illustrate and not to limit.

Referring initially to FIG. 1, an embodiment of a gripping device 10holding a cylindrical object 12, such as a test tube, is illustrated.According to the illustrated embodiment, the gripping device 10comprises two gripping springs 72 a, 72 b. FIG. 2A shows one embodimentof gripping springs 72, and FIG. 2B shown an alternate embodiment ofgripping springs 72. As shown in FIGS. 2A and 2B, each gripping spring72 may include a first end 94 and a second end 95. The gripping springs72 a, 72 b may possess a substantially straight section 91 and anarcuate section 92, as illustrated in FIGS. 2A and 2B, such that thearcuate sections 92 of the gripping springs 72 a, 72 b are configured topartially surround and/or conform to the curvature of the cylindricalobject 12 when the gripping device 10 is actuated. Continuing to referto FIG. 2, the first end 94 of the gripping spring 72 may be disposednear the substantially straight section 91, and the second end 95 of thegripping spring 72 may be disposed near the arcuate section 92. Turningback to FIG. 1, the first ends 94 a, 94 b of the gripping springs 72 a,72 b may be pivotally coupled to a body 11 of the gripping device 10through pivot pins 84 a, 84 b. The second ends 95 a, 95 b may be securedto respective drive (or finger) links 76, 77 via link pins 82 a, 82 b,respectively. The drive links 76, 77, which may comprise one or morepieces, may be pivotally coupled to the actuating link 79 via respectivepivot pins 83 b and 83 a. It is understood that any or all of the pivotpins may comprise any conventional or yet to be developed pivotalconnection device such as bearings, bolt-nut connections, etc. As analternative embodiment, the drive links 76, 77 may each comprise twopieces, an upper piece and a lower piece (not shown), which are heldtogether via screws 85 a, 85 b.

The gripping device 10 may further comprise an actuator such as, forexample, a solenoid 15. As illustrated in the example, a mounting plate16 may be coupled to a rotary shaft of the solenoid 15 such thatrotation of the rotary shaft of the solenoid 15 causes correspondingrotation of the mounting plate 16. As shown in FIG. 1, the drive links76, 77 may be coupled directly to the mounting plate 16 via pivot pins83 a and 83 b, respectively. In an alternative to the embodiment shownin FIG. 1, the actuating link 79 may be removed as unnecessary. Asconfigured, the rotation of the rotary shaft of solenoid 15 in aclockwise direction as shown by arrow 86 a causes the mounting plate 16to also rotate in a clockwise direction, thus causing the drive link 76to travel in a substantially linear direction away from the mountingplate 16 as indicated by arrow 86 c; similarly this may cause drive link77 to travel in a substantially linear direction toward the mountingplate 16 as indicated by arrow 86 b. Such movement of drive links 76 and77 cause the arcuate sections 92 of the gripping springs 72 a, 72 b toat least partially enclose around and grip the cylindrical object 12,thus move into a gripping position about the cylindrical object 12.

Rotation of the rotary shaft of solenoid 15 in a counterclockwisedirection (i.e., a direction opposite to arrow 86 a) may have anopposite effect (i.e., drive link 76 move in direction opposite of arrow86 c and drive link 77 move in direction opposite to arrow 86 b) and maycause the arcuate sections 92 of the gripping springs 72 a, 72 b torelease the cylindrical object 12. In this fashion, operation of theactuator (e.g., solenoid 15) may cause the gripping springs 72 a, 72 bto effectively and safely grip (i.e., gripping position) and/or release(i.e., a release position) the cylindrical object 12. The actuating link79 (or mounting plate 16) may be actuated or rotated in any number ofways, including, but not limited to, manual rotation, servo motor,rotary pneumatic motor and/or cam plate.

Alternatively, an actuator, such as solenoid 15, may be coupled directlyto the actuating link 79 so as to be able to rotate the actuating link79, thus producing a substantially linear motion (as illustrated bydirection arrows 86 a and 86 b) in the drive links 76, 77. As anexample, see embodiments shown in FIGS. 5-8, wherein the rotary shaft ofthe solenoid is pivotally connected directly to actuating link 79. Asthe solenoid 15 is actuated in either embodiment, the actuating link 79(or mounting plate 16) is rotated about an axis defined by the rotaryshaft of solenoid 15 (e.g., the pivot axis of the mounting plate 16 oractuating link 79 is coaxial to the rotational axis of the rotary shaftof solenoid 15).

The drive links 76 and 77 and the actuating link 79 may be made ofsteel, aluminum, composite material, plastics, or other appropriatematerials. The lengths of the links 76, 77 and 79 may be adjusted toprovide for larger or smaller diameter cylindrical objects, or toprovide larger or smaller gripping torque.

Referring again to FIGS. 2A and 2B, the gripping spring 72 may comprisean inner spring 88 that may be made of a flexible material, such assteel, and be configured such that each end possesses a first end 94 anda second end 95. The inner spring 88 comprises a substantially straightsection 91 and an arcuate section 92 (i.e., the compliant grippingportion) configured to wrap, flex around, and/or substantially conformto a cylindrical object (e.g., cylindrical object 12). The substantiallystraight section 91 may be configured to provide the gripping tension.The gripping spring 72 may further comprise a high-friction material 90,such as elastomers, urethane, etc., that surrounds the inner spring 88and/or covers a portion, if not all of, the gripping spring 72. Thehigh-friction material 90 may be applied to the inner spring 88 by wayof molding or other appropriate processes. Gripping springs 72 mayinclude one or more slots 93 defined in the inner spring 88 that may aidin bonding the high-friction material 90 to the inner spring 88.

As illustrated in FIG. 1, a cylindrical object 12 may be initiallyplaced into a gripping area 14 (i.e., spaced defined by opposed grippingsprings 72 a and 72 b) while the gripping device 10 is in an openedposition and ready to receive the cylindrical object 12. To grip thecylindrical object 12, the actuating link 79 (or mounting plate 16) isrotated or pivoted in a suitable direction for proper gripping thecylindrical object 12 with the gripping springs 72 a and 72 b (e.g.,clockwise direction 86 a in FIG. 1). As the actuating link 79 (ormounting plate 16) rotates or pivots, the drive links 76, 77 move in asubstantially linear fashion (e.g., direction 86 c and 86 b,respectively), which causes the gripping springs 72 a, 72 b to at leastpartially wrap around and/or grip the cylindrical object 12. Althoughnot to be limited by theory, it is believed that the arcuateconfiguration of the gripping springs 72 a, 72 b assist in guiding thecylindrical object to a centered position within the gripping area 14,thus providing an automatically self-centering benefit to the gripingdevice 10. For example and again not to be limited by theory, assume acylindrical object 12 is placed into the gripping area 14 and isinitially closer to drive link 76 than it is to drive link 77 (i.e., thecylindrical object 12 is not centered). When the gripping springs 72 a,72 b are actuated to a gripping position as shown in FIG. 1, the arcuatesection of the gripping spring 72 a may initially contact thecylindrical object 12 at a point relatively close to the second end (notshown), while the arcuate section of the gripping spring 72 b mayinitially contact the cylindrical object 12 at a point relatively farfrom the second end (not shown). Due to the slightly different contactlocations on the gripping springs 72 a, 72 b, the cylindrical object 12may be forced to the center of the gripping area 14 as the grippingsprings 72 a, 72 b, continue to wrap around the cylindrical object.

As another example of self-centering, and not to be limited by theory,assume a cylindrical object 12 is placed into the gripping area 14 andis initially closer to gripping spring 72 a than gripping spring 72 b(i.e., the cylindrical object 12 is not centered). When the grippingsprings 72 a, 72 b are actuated into a gripping position, the grippingspring 72 a may initially contact the cylindrical object 12 first, thuspushing the cylindrical object 12 toward gripping spring 72 b. As bothgripping springs 72 a, 72 b continue to close, gripping spring 72 b willeventually contact the cylindrical object 12 as well. In this fashion,the actuation of the gripping springs 72 a, 72 b may cause thecylindrical object 12 to automatically be centered as they come intocontact with and wrap around the cylindrical object 12 (i.e., grippingposition).

Because the actuator (e.g., solenoid 15) and any associated componentsmay be physically offset from the cylindrical object 12, the grippingdevice 10 may have a compact configuration. The gripping device 10 alsomay provide for self tightening and self locking. This may be due to thedesign of the gripping springs 72 a, 72 b. For example, as shown in FIG.1, the gripping springs 72 a, 72 b may hold a cylindrical object 12 whenthe gripping device 10 is actuated. As the cylindrical object 12 is heldby the gripping springs 72 a, 72 b, any attempted rotation (e.g., in aclockwise direction indicated by arrow 86 a) of the cylindrical object12 may cause the gripping springs 72 a, 72 b to further wrap around thecylindrical object 12 due to the mechanical coupling of the grippingsprings 72 a, 72 b to the cylindrical object 12. This may provide anadditional self-tightening function benefit for the gripping device 10and may help prevent the cylindrical object 12 from rotating within thegripping springs 72 when external rotational forces are placed upon it(e.g., when a cap is being removed from the cylindrical object 12).

Moreover, the simple configuration allows for the gripping device 10 totighten about a cylindrical object 12 in one direction (e.g., mountingplate 16 and/or actuating link 79 moves in a clockwise direction asindicated by arrow 86 a according to one embodiment) and loosen about acylindrical object 12 in the opposition direction (e.g., mounting plate16 and/or actuating link 79 moves counter-clockwise according to oneembodiment). The use of the gripping springs 72 a, 72 b, mounting plate16 (and/or actuating link 79) and drive links 76 and 77 may allow forthe accommodation of a large variation in diameters and/or widths of thecylindrical objects 12. More particularly, because the gripping springs72 a, 72 b at least partially wrap around the cylindrical object 12,compliance with many different sized and shaped cylindrical objects maybe achieved. For example, cylindrical objects having sharp edges (e.g.,an object having a hexagonal cross section) may be accommodated by thegripping device 10. Also, cylindrical objects which do not have asymmetrical cross section may be accommodated as well. In short, thegripping device may be able to accept a variety of objects havingvarious shapes and sizes.

The self-tightening or self-locking feature may also enable the use ofrelatively small actuating forces to generate large gripping forces.Torque ratio, as used herein, is defined as the ratio between theactuating torque (e.g., generated by solenoid 15) and the grippingtorque (e.g., the torque acting on and/or applied to the cylindricalobject 12 when gripped by the gripping device 10). The torque ratio maybe smaller for cylindrical objects having a smaller diameter. The use ofhigh-friction materials 90 (e.g., elastomers) of different durometersslightly changes the amount of gripper torque achieved, but the torqueratio remains very similar.

As an example and not a limitation, an experiment was performed on agripping device 10 to determine the affect of different high-frictionmaterial 90 (i.e., elastomer) durometers on actuating torque and theresulting gripper torque as applied to two sizes of glass tubes (e.g.,10 mm and 16 mm). A torque gage was used to generate the actuatingtorque while the resulting gripping torque was measured with a digitaltorque wrench. The durometer of the elastomer had a range from 21A to65A (“A” scale). As illustrated FIGS. 3A and 3B, the actuating torquewas within a range of 0.2N-m to 0.6 N-m and resulted in a gripper torquerange of 0.2 N-m to 1.1 N-m, and a torque ratio from about 0.5 to 2.8depending on the test tube size and durometer. Referring to FIG. 3A, thetorque ratio (slope) remained very similar for the durometers of 65, 36and 21 that were tested on 16 mm tubes. Referring to FIG. 3B, the torqueratio (slope) is shown when applied to 10 mm tubes.

The embodiments of the gripping device 10 described above may beimplemented into automated cap removal applications. For example, anembodiment of an automated cap removal system 108 is illustrated inFIGS. 4-9. The cap to be removed from the cylindrical object by theautomated cap removal system 108 may be a screw cap, cork, plug, orother similar device which may close off or seal a cylindrical object,such as a test tube. The cap may have a different shape and/or size(e.g., diameter) than the cylindrical object. Still referring initiallyto FIGS. 4-9, the illustrated cap removal system 108 comprises adecapping assembly 18, a holding and indexing assembly 68, a linearslide 40 and a servo motor 98. Generally, as a system overview, the capremoval system 108 removes caps or plugs from cylindrical objects as setforth above herein, such as test tubes, by holding a bottom portion ofthe cylindrical object at the holding and indexing assembly 18 while thedecapping assembly 18 is lowered along the linear slide 40 onto the capof the cylindrical object. The decapping assembly 18 secures the capwith a gripping device 10D (FIG. 9), twists and then pulls the cap outof or from the cylindrical object by raising back up along the linearslide 40. The decapping assembly 18 and its respective gripping device10D will be described in detail below herein.

More particularly, the holding and indexing assembly 68 comprises anindexing plate 70 having three stations 60A, 60B and 60C. Although theillustrated embodiment comprises a three-station indexing plate 70, itis contemplated that other embodiments may comprise more or fewerstations. Each station 60A-C comprises a respective gripping device 10A,10B, and 10C that is operable to grip and/or hold a cylindrical objectas described above (see FIG. 6). According to the illustratedembodiment, each station also comprises a locator plate 75, whichfurther comprises a guide 69 and an insert 73 for easy insertion andlocation of a cylindrical object. Insert 73 includes fingers that may bespring-biased inwardly which hold and center the cylindrical objectwithin the gripping area 14 until the gripping springs 72 a and 72 bgrip the cylindrical object. It is understood that stations 60B and 60Ccomprise substantially the same components as station 60A and thus willnot be described herein. The actuating link 79 is rotably attached tothe indexing plate 70 by a pivot pin 83 a assembly as illustrated inFIG. 8. The pivot pin 83 a assembly is connected to a cam followerbearing 87 on the underside of the indexing plate 70. One end of each ofthe actuating links 79 is attached to two of three springs 71 a-c thatconnect to each actuating link 79 positioned on the indexing plate 70.The springs 71 a-c aid the gripping springs 72 in at least partiallywrapping around, gripping, and/or conforming to the cylindrical object.The same end of the each actuating link 79 is also pivotally connectedto a drive link 77 via pivot pin 83a (FIG. 6) which is configured toslideably rest in arcuate slot 80.

According to the illustrated embodiment, the indexing plate 70 isindexed (i.e., rotated) by servo motor 98 (FIG. 4). The indexingassembly 68 may have three indexing positions 62X, 62Y, and 62Z suchthat the indexing positions 62X-Z are substantially fixed with respectto the indexing assembly 68 and the indexing plate 70 may be indexed(e.g., rotated) between the indexing positions 62X, 62Y, and 62Z.Generally, there may be the same number of indexing positions (e.g.,positions 62X-Z) as stations (e.g., stations 60A-B), such that onestation may be disposed at a single indexing position at any particulartime. For example, as illustrated in FIG. 5, station 60A may be disposedat indexing position 62X, station 60B may be disposed at indexingposition 62Y, and station 60C may be disposed at position 62Z. Theindexing plate 70 may be indexed such that each one of the stations60A-C may be disposed at any of the indexing positions 62X-Z. Incontinuing with the above example, the indexing plate 70 may be indexedclockwise 120 mechanical degrees such that station 60C may be disposedat indexing position 62X, station 60A may be disposed at indexingposition 62Y, and station 60B may be disposed at indexing position 62Z.As shown in FIG. 5, the indexing assembly 68 may also comprise an indexgripping cam 24 which permits the indexing plate 70 to only index(rotate) in one direction. The system may be designed so that theindexing plate 70 is indexed counterclockwise, if desired.

Each of the indexing positions 62X-Z may perform a specific function inthe decapping process. For example, at indexing position 62X, a firstcylindrical object may be inserted into the insert 73 of a firstgripping device indexed at this position (e.g., gripping device 10A ofstation 60A); once the gripping device is indexed from indexing position62X to 62Y, the first cylindrical object held by insert 73 may begripped by the first gripping device indexed at this position (e.g.,gripping device 10A) while the decapping assembly 18 is lowered alongthe linear slide 40 to grip a cap on this first cylindrical object withthe gripping device 10D and to twist the cap while the decappingassembly 18 is raised back up along the linear slide 40 to remove thecap from the first cylindrical object; and finally, once the firstgripping device is indexed from position 62Y to 62Z, the firstcylindrical object may be released by the first gripping device (e.g.,first gripping device 10A). Thus, when a indexing station 60A-C and itscorresponding gripping device 10A-C is indexed at a correspondingindexing position (e.g., indexing positions 62X, 62Y, and 62Z,respectively as shown in FIG. 5), the operations at each of thesecorresponding indexing stations and positions may be performedsimultaneously,

Continuing to follow this example, as the gripping device 10A is indexedat position 62X, the gripping device 10B will be located at station 62Y,and the gripping device 10C will be located at 62Z wherein thecorresponding operations will be performed at the respective positionsas set forth above. Similarly, as the gripping device 10A is indexed atposition 62Y, the gripping device 10B will be located at station 62Z,and the gripping device 10C will be located at station 62X, wherein thecorresponding operations will be performed at the respective positionsas set forth above. Also, as the gripping device 10A is indexed atposition 62Z, the gripping device 10B will be located at station 62X,and the gripping device 10C will be located at station 62Y, wherein thecorresponding operations will be performed at the respective positionsas set forth above. In this fashion, the indexing positions 62X-Z mayperform specific functions in parallel such that the throughput of theoverall decapping process is improved. Other indexing positions may beadded, if desired, which may provide additional functionality.

Rather than actuating the gripping devices 10A-C by a rotary solenoid,the illustrated embodiment actuates the gripping devices 10A-C by a cam(not shown) and a cam follower bearing 87. Each gripping device 10A-Ccomprises its own respective cam follower bearing 87A-C. The cam ispositioned under the indexing plate 70 and shaped such that the camfollower bearings 87A-C engage and disengages the cam depending uponwhat indexing position an indexing station is located at. For example,the cam follower bearings 87A-C do not engage the cam at indexingpositions 62X or 62Z, and therefore, when at these positions, thegripper devices 10A-C are in an open position. In an open position, thegripping devices are not gripping a cylindrical object. As the indexingplate 70 is indexed (i.e., rotated) such that an indexing station 60A-Cand its respective gripping device 10A-C is indexed into position 62Y,the cam follower bearing 87 contacts and engages the cam, which causesthe actuating link 79 to rotate at this indexing position. As shown inFIG. 6, as the actuating link 79 rotates (e.g., counterclockwise), pivotpin 83 a moves within arcuate slot 80 and both gripping springs 72 a and72 b wrap and/or flex around and grip the cylindrical object asdescribed above. Finally, as the table rotates one more time, and thestation moves to indexing position 62Z, the cam follower bearing 87 nolonger engages the cam, which causes the actuating link 79 to rotate theopposite direction (e.g., clockwise) moving the two respective grippersprings (e.g., 72 a and 72 b) to an open position. As such, the grippingsprings releases the cylindrical object, which may now be removed fromthe gripping device by manual or automatic methods. In this manner, thegripping devices 10A-C are actuated without the need for additionalservo motors, solenoids or the like.

As set forth above, at indexing position 62Y, the decapping assembly 18,which comprises a timing sprocket 20 with the gripping device 10D (FIG.9) enclosed therein, may travel down the linear slide 40 via a linearservo motor 38 (FIG. 4) and grip, twist, and pull a cap off and/or froma cylindrical object. For example and referring to FIG. 9, the grippingdevice 10D may be positioned inside of the timing sprocket 20. Thetiming sprocket 20 may have a recess 19 within which the gripping device10D is located. The drive links 76 and 77 may be of a longer length thanthe lengths of the holding gripping devices 10 10A-C described above toadd more stroke in order to more effectively grip the cap or plug.According to one embodiment, the gripping device 10D is actuated by arotary solenoid 34 that is mounted on top of the timing sprocket 20 andcoupled to the actuating link 79 via adapter plate 32. The rotarysolenoid 34 may be mounted onto the timing sprocket 20 via housing 36and related hardware. Referring to FIGS. 5 and 9, a timing belt 21 ispositioned around the teeth 28 of the timing sprocket 20 and a servomotor 22 which drives the timing belt 21 as described above. A tensionpulley 23 may also be provided in order to keep a relatively constanttension on the timing belt 21. The servo motor 22 rotates the decappingassembly 18 to provide the twisting motion that aids in removing the capfrom the cylindrical object.

More specifically, as the indexing plate 70 rotates and a cylindricalobject is positioned under the decapping assembly 18, the decappingassembly vertically slides down the linear slide 40 such that the cap ispositioned within the opened gripping device 10D that is incorporatedinto the timing sprocket 20. The rotary solenoid 34 is actuated, whichthen rotates actuating link 79, thereby causing the gripping springs 72a and 72 b to wrap around the cap of the cylindrical object. After thecap is gripped by the gripping device 10D, the decapping assembly 18both rises on linear slide 40 and rotates via the servo motor 22. Thesetwisting and pulling motions remove the cap or plug from the cylindricalobject. As the indexing plate 70 is indexed, the rotary solenoid 34 isthen de- actuated which causes the gripping device 10D to release thecap, assisted by the springing force provided by the ejector pinassembly 30. In an alternative embodiment, the cap may also be ejectedfrom the decapping assembly by a solenoid-driven ejector pin. The timingof the release of the cap and the rotation of the indexing plate 70 issuch that the cap falls into a chute or a bin between decapping stationsas the indexing plate 70 is indexed. The indexing plate 70 is shaped andconfigured so that the cap may fall into the chute between stations.

Having described the invention in detail and by reference to specificembodiments thereof, it will be apparent that modifications andvariations are possible without departing from the scope of theinvention defined in the appended claims. More specifically, althoughsome aspects of the present invention are identified herein as preferredor particularly advantageous, it is contemplated that the presentinvention is not necessarily limited to these preferred aspects of theinvention.

The above description and drawings are only to be consideredillustrative of the embodiments, which achieve the features andadvantages of the present invention. The invention is not to beconsidered as being limited by the foregoing description and drawings,but is only limited by the scope of the appended claims.

What is claimed is:
 1. A device for gripping a cylindrical object, thedevice comprising: a body; a first gripping spring having a first endand a second end opposite the first end, the first end of the firstgripping spring coupled to the body; a second gripping spring having afirst end and a second end opposite the first end, the first end of thesecond gripping spring coupled to the body; a first drive link coupledto the second end of the first gripping spring; a second drive linkcoupled to the second end of the second gripping spring; an actuatorcoupled to at least one of the first or second gripping springs suchthat a first movement of the actuator moves the first and secondgripping springs from a first position to a second position and a secondmovement of the actuator moves the first and second gripping springsfrom the second position to the first position; wherein the first andsecond gripping springs oppose each other so as to define a grippingarea.
 2. The device of claim 1, wherein the first gripping springcomprises an arcuate section and the second griping spring comprises anarcuate section, wherein the arcuate sections of the respective firstand second gripping springs form the gripping area.
 3. The device ofclaim 1, wherein the first and second movements are rotationalmovements.
 4. The device of claim 1, wherein the first and secondmovements are linear movements.
 5. The device of claim 1, wherein thefirst and second gripping springs are compliant gripping springs.
 6. Thedevice of claim 1, wherein at least a portion of the first grippingspring and at least a portion of the second gripping spring comprises ahigh friction material.
 7. The device of claim 6, wherein the highfriction material is a material selected from the group consisting ofelastomer, urethane, and combinations thereof.
 8. The device of claim 1,wherein the actuator is a device selected from the group consisting of amanual actuator, servo motor, rotary solenoid, rotary pneumatic motor,and cam actuator.
 9. The device of claim 1, wherein the actuator is acam bearing and corresponding cam plate.
 10. The device of claim 1,wherein the first position is a gripping position and the secondposition is a release position.
 11. The device of claim 1, furthercomprising an actuating link pivotally coupled to the first and seconddrive links, wherein the actuator is pivotally coupled to at least oneof the first drive link, the second drive link or the actuating link.12. The device of claim 11, wherein the actuator is pivotally coupled tothe first and second drive links.
 13. The device of claim 12, whereinthe respective ends of the first and second drive links are pivotallycoupled to the second ends of the respective first and second grippingsprings.
 14. The device of claim 11, wherein the actuator is pivotallycoupled to the actuating link.
 15. The device of claim 14, wherein therespective ends of the first and second drive links are pivotallycoupled to the second ends of the respective first and second grippingsprings.
 16. The device of claim 1, wherein: the first end of the firstgripping spring is pivotally coupled to the body; the first end of thesecond gripping spring is pivotally coupled to the body; the first drivelink is pivotally coupled to the second end of the first grippingspring; the second drive link is pivotally coupled to the second end ofthe second gripping spring; and the actuator is pivotally coupled to atleast one of the first gripping spring or the second gripping spring.17. A device for gripping a cylindrical object, the device comprising: abody; a first gripping spring having a first end, a second end oppositethe first end, and an arcuate section disposed therebetween, the firstend of the first gripping spring pivotally coupled to the body; a secondgripping spring having a first end, a second end opposite the first end,and an arcuate section disposed therebetween, the first end of thesecond gripping spring pivotally coupled to the body; a first drive linkpivotally coupled to the second end of the first gripping spring; asecond drive link pivotally coupled to the second end of the secondgripping spring; an actuating link pivotally coupled to the first andsecond drive links; an actuator pivotally coupled to at least one of thefirst drive link, the second drive link or the actuating link andcoupled to at least one of the second ends of the first and secondgripping springs such that the actuator moves the first and secondgripping springs between a first position and a second position; whereinthe arcuate sections of the first and second gripping springs opposeeach other so as to define a gripping area.
 18. A method of gripping acylindrical object, the method comprising: actuating the device of claim17 such that the first and second gripping springs move to the firstposition; inserting a cylindrical object into the gripping area definedby the first and second gripping springs; and actuating the first andsecond gripping springs from the first position to the second positionsuch that the first and second gripping springs grip the cylindricalobject disposed within the gripping area.
 19. The method of claim 18,further comprising actuating the first and second gripping springs fromthe second position back to the first position such that the first andsecond gripping springs release their grip on the cylindrical object andremoving the cylindrical object from the gripping area.
 20. A method ofremoving a cap from a test tube, comprising: inserting a test tube intoa gripping area defined by a first gripping spring and a second grippingspring of a gripping device, wherein the gripping device comprises: abody, the first gripping spring having a first end and a second endopposite the first end, the first end of the first gripping springcoupled to the body, the second gripping spring having a first end and asecond end opposite the first end, the first end of the second grippingspring coupled to the body, a first drive link coupled to the second endof the first gripping spring, a second drive link coupled to the secondend of the second gripping spring, and an actuator coupled to at leastone of the first or second gripping springs such that such that theactuator moves the first and second gripping springs between a firstposition and a second position; actuating the first and second grippingsprings to grip the test tube disposed within the gripping area;inserting a cap that is connected to an open end of the test tube into agripping area of a second gripping device; actuating the second grippingdevice to grip the cap; rotating the second gripping device while thecap is gripped by the second gripping device; and moving the secondgripping device away from the test tube while the cap is gripped by thesecond gripping device.